924Board.org

[ScorpioGT]

I know that every possible aspect of tuning is covered here, and very well, but what i seek is a suggestion on the way i should tune my loved 924 in order to get the best performance and reliability and enjoyment.
I saw a lot of different opinions on tuning stock 2.0 NA engines. some says it gets HP and quality power (good torque range, reliability etc.), some says it's a waste of time and money.
To get the best suggestions, i will say what i want to achieve first:

-At least 220 wheels HP, the more the better
-Good reliability also for normal road usage
-Ultimate lightweight and stiffness

Do you reckon it's better to turbo the 2.0 NA? (i've read Racerboy did some very good stuff) or swap to another engine? My idea was an Audi 20V turbo, which reaches monster HP with good reliability.
Any other good idea or option or combination is more than welcome.
Some tips on the cash that each option would roughly cost me, would also be great.
Thank you guys.
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1982 - 924 2.0 NA - racing project

[ideola]

You're unlikely to achieve that HP goal with an NA (the DProd cars were only getting 180BHP, and they were very highly strung, frequently blowing head gaskets, and requiring rebuilds between each race weekend).

So your choices are forced induction or engine swap.

I have believed for a long time that the least expensive and least difficult path to forced induction on the NA would be to install a belt-driven supercharger (think Vortech) installed in the same location as the 931 alternator. This would require removing CIS and changing to EFI, but you would probably want to do that anyway to achieve your reliability and tuning goals.

The beauty of such a setup is that you wouldn't have change anything else on the motor. No exhaust mods, no relocation of the NA alternator, and you could even keep A/C (if you have it). The belt driven supercharger is light, and it would be quite easy to plumb in an intercooler. All of this could be done without even pulling the existing motor. With the right approach, it could be essentially bolt-on, with extremely minor fabrication requirements...a little bit of engineering on the 931 alternator mount bracket, a couple of brackets for an intercooler, and the intercooler piping. That's about it (excluding the EFI, of course).

It's also worth mentioning, if your car doesn't have A/C, or if you didn't care about retaining A/C, you could put the supercharger there and not even have to mess with EFI.

Compared to an engine swap, and all that would entail, I think the belt-driven supercharger would be easier and cheaper to complete.
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erstwhile owner of just about every 924 variant ever made

[ScorpioGT]

Thanks Ideola. That looks like an interesting alternative. Do you know somebody who successfully completed this?
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1982 - 924 2.0 NA - racing project

[Cedric]

Enjoy some turbo conversion reading here!

http://www.924board.org/viewtopic.php?t=38765&highlight=
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1980 924 Turbo
www.instagram.com/garagecedric/

[ideola]

[leadfoot]

because they are expensive and not readily available second hand...
stu
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1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

[ScorpioGT]

Thank you guys

[snakoil]

I actually have a belt dirven supercharger and removed my AC(kept the brackets around to use for the SC)
I did not dare starting to put it in as I was under impression EFI was a requiered step for this as it changed the AF.

I see here that the OEM CIS system would be good enough, I'M gessing it would still need to be tuned a bit to send more gas now that it has more air otherwise it would run lean...or is CIS system so wise it can compensate automatically?
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1979 924 NA